Grass mowing machines such as greens mowers, fairway mowers and trim mowers are commonly equipped with several reel mower cutting units to provide a high quality of cut for golf courses. Each reel mower cutting unit may have a generally horizontally-aligned cutting reel, and front and back rollers or caster wheels that roll in contact with the ground for supporting the unit during operation. Blades of the rotating reel interact with a bedknife to cut grass with a scissoring action. Each reel mower cutting unit may be attached to the outer end of a lift arm extending laterally outwardly from a traction vehicle.
These machines may include implement lift systems to raise and lower the cutting units on the outer ends of the lift arms. Implement lift systems for mower cutting units may include hydraulic cylinders connected to the lift arms, or electric motors driving linear actuators. For example, a hydraulic cylinder attached to a lift arm may be extended to raise a cutting unit to a transport or service position, and retracted to lower the cutting unit to a mowing position. Examples of grass mowing machines with hydraulic implement lift systems for mower cutting units are provided in U.S. Pat. Nos. 5,297,378 and 5,343,680. Examples of grass mowing machines having electric implement lift systems for mower cutting units are shown in U.S. Pat. Nos. 5,540,037 and 5,553,445.
As the implement lift system lowers a reel mower cutting unit onto a sloped surface of a golf course, the first part of the unit to touch the ground may leave a mark on the turf. Additionally, the left or right side of a reel mower cutting unit may damage the turf as the unit slides sideways after one side reaches the ground surface. It is desirable to prevent marks caused by lowering reel mower cutting units onto sloped surfaces of a golf course, and to prevent damage to the turf as the unit slides sideways after one side reaches the ground surface.